Apparatus for and method of forming internal threads by stamping dies



Jan. 2, 1934. K, BERGER I 1,942,353

APPARATUS FOR AND METHOD OF FORMING INTERNAL THREADS BY STAMPING DIES FiledNov. 22. 1932 INVENTOR KORNEL BERGER,

ATTORNEfi Patented Jan. 2, 1934 UNITED STATES APPARATUS FOR AND METHOD OF FORM- ING INTERNAL THREADS BY STAMPING DIES Kornel Berger, New York, N. Y.

Application November 22, 1932- Serial No. 643,849

17 Claims.

This invention relates to new and useful improvements in a frame construction for use in the manufacture of lamp shades and the method of forming threads thereon.

The invention has for an object the provision of a frame construction as mentioned which is characterized by being formed from a stamped sheet of metal arranged so as to have internal threads as required.

As a still further object of this invention it is proposed to construct a die to manufacture the frame construction in a manner so that upon each closing of the die a complete article is pro-- duced, said article being produced in three steps within the die, arranged in proper sequence so that the final step completes the article.

The invention still further proposes the construction of a die which is provided with means for automatically stamping a legend upon the article.

Still further it is proposed to arrange the die in a manner so as to be equipped with removable small spiral dies adapted to stamp spiral grooves upon portions of the sheet metal thereafter turned inwards to form the screw threads previ ously mentioned.

Furthermore the invention proposes the provision of means upon the die adapted to eject the finished article after completion.

As another object of this invention it is pro posed to construct a device as mentioned which is simple and durable and which can be manufactured and sold ata reasonable cost.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawing forming a material part of this disclosure:

Fig. 1 is a plan view of the bottom block of the die.

Fig. 2 is an edge elevational view looking in the direction of the line 22 of Fig. 1.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1.

Fig. 4 is a bottom view of the punch block of the die.

Fig. 5 is a side elevational view looking in the direction of the line 55 of Fig. 4.

Fig. 6 is a fragmentary sectional view taken along the line 6-6 of Fig. 4 showing in particular the ejecting means for ejecting the finished article.

Fig. 7 is a fragmentary view of a strip of metal upon which two steps of the method have been performed.

Fig. 8 is a perspective view of the completed article.

The frame construction according to this invention is shown in perspective detail in Fig. 8 and comprises a circular member 10 having a downturned outer edge 11 formed with a plurality of lugs 12 each having an opening 13, and a downturned inner edge 14 stamped with threads. This particular article is intended for use in the manufacture of lamps. It is extremely simple and is formed from sheet material produced 100% by stamping including the forming of the threads upon the inner downturned edge.

The die for the manufacture of the frame construction described in the previous paragraph comprises a bottom block 15 formed from several layers of metal connected together and arranged with elements adapted to coact with complementary elements on a punch block 16 adapted to be used in a customary press. The bottom block 15 is arranged at the side with notches 17 to facilitate its attachment upon the bed of a punch press. A plurality of posts 18 project from the bottom block 15 and are adapted to slidably engage within openings 19 formed in the punch block 16 so as to properly direct the closing of these parts.

The coacting elements upon the bottom and punch blocks are arranged in a manner so that a strip of metal may be continuously interruptedly moved between blocks and periodically the punch block be lowered for operating upon the strip, the left hand end of this strip is shown with two stages of operation. The first stage of operation performed by the die is the blanking out of the metal for the manufacture of the frame construction shown in Fig. 8. This blanking out is accomplished by the provision of openings 22, 23 and 24 formed in the bottom block 15 and adapted to co-operate with complementary solid cutting elements 22 23 and 24 projecting from the punch block 16. The elements 22, 22' are adapted to cut out the space 25 of the strip 21 so as to form adjacent sides of two adjacent frame constructions. The elements 23 and 23' are adapted to form cutouts 26 at the top edge of the strip to form the upper side of the frame construction and opposing sides of lugs connecting the frame construction during the operationof the die. The elements 24 and 24' form the central opening of the blank.

Elements are also arranged for coacting with each other and upon bottom and punch blocks to stamp a legend upon the article and comprises particularly an opening 27 formed in the bottom block 15 and adapted to co-operate with a legend punch 28 projecting from the punch block 16. This legend punch engages at the area 29, see Fig. 7, upon the strip 21 so as to immediately place the legend upon the strip at a portion which will thereafter form the circular member 10 of the article. The blank formed by the first stage of the die operation comprises a circular member 10' and a plurality of prongs or lugs 12 projecting radially therefrom. Each of these lugs is formed with the apertures 13 as previously recited and these apertures are automatically produced by the provision of three openings 30, 31 and 32 upon the bottom block 15 and adapted for coacting with punch rods 30', 31 and 32' projecting from the punch block 16.

The elements 30 and 30' are arranged to punch a hole 13 to the right of the legend 29 which forms the opening 13 upon the right upper lug of the circular member 10- when the strip is next advanced. The elements 31 and 31' form the opening 13 in the bottom'lug of the blank, that is, the lug immediately below the opening 2'7. The elements 32 and 32' form the opening 13 upon the lug 12 at the left hand side of the blank 10. The several members of the bottom block 15 are held together by bolts 35 while the several members of the punch block 16 are held together by bolts 36.

The second phase of the operation of the die is to stamp the threads upon both sides of the blank 10 shown in Fig. 7. This blank previously had the position 10' but when the strip is moved over it assumes the position 10. In order to stamp the threads upon this blank there is provided a die comprising a bottom section 37 having a thread-stamping face formed with a spiral groove 38 and mounted upon the bottom block 15 and coactable with a complementary die section 39 having a thread-stamping face also formed with a spiral groove mounted upon the punch block 16. The elements 37 and 39 are adapted to form the threads 40 along the inside diameter of the blank 10. The last step of the formation of the article by the die comprises the cutting off of the article from the remaining portions of the metal strip and the formation thereof.

In detail to accomplish the steps set forth above a cylindrical member 41 is secured upon the bottom block 15 concentric within a circular recess 42 formed in the bottom block 15. The punch block 16 is equipped with a cup shaped die 43' having an outer cutting edge 44 adapted to coact with the top edge of the opening 42 so as to cut the lugs 12 apart. In detail the lugs will be cut along the lines 45 shown in Fig. The cup 43 is provided with a bending post 46 having a reduced head 47 adapted to engage into the centre of the opening 27 and bend the centre of the blank into the area between the cup 43 and the post. An ejecting ring 48 is slidably mounted between the post 46 and the cup 43 and normally assumes a retracted position so as not to interfere with the bending operation. A rod 49 is connected with the ring 48 and extends out from the punch block 16 and is adapted to be moved during the opening of the press so as to cause the ejection of the ring 48 and the consequent ejection of the finished article. To insure the proper ejection, an ejecting pin 50 is mounted upon the rim of the ring 48 and is resiliently urged outwards by a spring 51.

portion of the die cuts off the finished article The strip of metal 21 is fed in between the blocks of the die and upon each feeding the punch block of the die is brought against the bottom block by the operation of the press. Consequently all of the various steps of operation of the dies take place simultaneously, that is, the right hand end portion of the die forms the blank 10, the central portion of the die places the threads 40 upon the portion 10 and the left hand from the strip and forms it into the shape shown in Fig. 8. The finished article will cling upon the cup 43, in that, the prongs 12 will engage within the inner diameter of the cup 43 and the flange 11 against the outside diameter of the post 46 thus the finished article will be disposed in between the cup 43 and the post 46 and thereafter is ejected by the ejecting action of the ring 48. The strip 21 is fed along, one blank distance at a time so that each portion of the strip first assumes a position to be blanked indicated by reference numeral 10- then the same portion next assumes a position indicated by the reference numeral 10 and finally assumes the position in which it is severed from the strip and bent into proper form.

While I have shown and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.-

Having thus described my invention, what I claim as new-and desire to secure by United States Letters Patent is:

1. A die for the manufacture of a lamp shade frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and a still further adjacent position to cut the blank free and bend it into shape.

' 2. A die for the manufacture of a lamp shade frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, a means being also provided for guiding the blocks towards each other in proper alignment.

3. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and. then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, elements being also arranged to form apertures in lug portions of said blank.

4. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp 'the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, elements being also arranged to form apertures in lug portions of said blank, and elements being further provided 145 to form a. legend stamped upon the article.

5. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent posi- 150 tion to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, said blank form being shaped by the provision of elements adapted to out from one side of a metal strip a-portion forming adjacent bottom sides of adjacent blank forms, and cut out from the top a portion forming the top of the blank form, and also a central opening, and said elements to form threads upon an adjacent blank being arranged upon said bottom block and punch block and adapted to form the threads around-the said central opening.

6. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, said coacting element to cut out the blank and bend it comprising a cup shaped member on the punch block adapted to' engage within a circular opening on the bottom block, a cylindrical member within the circular opening on the bottom block for holding a portion of the blank form, a post projecting from the centre of said cup and adapted to engage within said cylindrical member to bend the area of the blank form around the central opening inwards at right angles to the main portion and thus form the spiral into threads, and an ejecting ring between said cup and post to eject the finished article.

7. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, said coacting element to cut out the blank and bend it comprising a cup shaped member on the punch block adapted to engage within a circular opening on the bottom block, a cylindrical member within the circular opening on the bottom block for holding a portion of the blank form, a post projecting from the centre of said cup and adapted to engage within said cylindrical member to bend the area of the blank form around the central opening inwards at right angles to the main portion and thus form the spiral into threads, and an ejecting ring between said cup and post to eject the finished article, means being provided for moving said ejecting ring.

8. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, said coacting element to cut out the blank and bend it comprising a cup shaped member on the punch block adapted to engage within a circular opening on the bottom block, a cylindrical member within the circular opening on the bottom block for holding a portion of the blank form, a post projecting from the centre of said cup and adapted to engage within said cylindrical member to bend the area of the blank form around the central opening inwards at right angles to the main portion and thus form the spiral into threads, and an ejecting ring between said cup and post to eject the finished article, means being provided for moving said ejecting ring, a resilient element being also mounted upon said ejecting ring to aid in the ejection of the article.

9. A die for the manufacture of a frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to first form a blank and then in an adjacent position to stamp the blank with threads and in a still further adjacent position to cut the blank free and bend it into shape, said coacting element to out out the blank and bend it comprising a cup shaped member on the punch block adapted to engage within a circular opening on the bottom block, a cylindrical member withinthe circular opening on thebottom block for holding a portion of the blank form, a post projecting from the centre of said cup and adapted to engage within said cylindrical member to bend the area of the blank form around the central opening inwards at right angles to the main portion and thus form the spiral into threads, and an ejecting ring between said cup and post to eject-the finished article, means being provided for moving said ejecting ring, a resilient element being also mounted upon said ejecting ring to aid in the ejection of the article, and comprising a peg, and a spring normally urging said peg outwards.

10. A die for the manufacture of a lamp shade frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to form a blank with lugs connected with the material from which said blank is being stamped and in an adjacent position to stamp the said blank with threads, .and in a still further adjacent position to cut the blank free and bend it into shape.

11. A die for the manufacture of a lamp shade frame construction, comprising a bottom block, a punch block, and coacting elements on said blocks to form a blank with lugs connected with the material from which said blank is being 115 stamped and in an adjacent position to stamp the said blank with threads, and in a still further adjacent position to out the blank free and bend it into shape, said coacting elements being also arranged so that the blank in the first position and the blank with the threads in the second position are connected by lugs.

12. A die for the manufacture of a lamp shade frame construction, comprising a bottom block,

a punch block, and coacting elements on said 125.

blocks to form a blank with lugs connected with the material from which said blank is being stamped and in an adjacent position to stamp the said blank with threads, and in a still further adjacent position to cut the blank free and bend it into shape, said coacting elements being also arranged so that the blank in the first .position and the blank with the threads in the second position are connected by lugs, said coacting elements being arranged to cut the lugs to free the blank.

13. A method for constructing a lamp shade frame member, consisting of stamping blanks from a strip of material in a manner so that lugs connect the blanks together and lugs connect the connected blanks with said strip, stamping a spiral groove on a certain of said blanks, cutting certain of said lugs to free said blank with the spiral groove, and bending the free blank into shape.

14. A method for constructing a lamp shade frame member, consisting of stamping blanks from a strip of material in a manner so that lugs connect the blanks together and lugs connect the connected blanks with said strip, stamp- 150 ing a spiral groove on a certain of said blanks, cutting certain of said lugs to free said blank with the spiral groove, and bending the free blank into shape, consisting of bending the area with the spiral groove to form a threaded cylindrical portion.

15. A method for constructing a lamp shade frame member, consisting of stamping blanks from a strip of material in a manner so that lugs connect the blanks together and lugs connect the connected blanks with said strip, stamping a spiral groove on a certain of said blanks, cutting certain of said lugs to free said blank with the spiral groove, and bending the free blank into shape, consisting of bending the area with the spiral groove to form a threaded cylindrical portion, and bending the lugs to be substantially parallel with the threaded portion.

16. A method for constructing a lamp shade frame member, consisting of stamping blanks from a strip of material substantially of circular shape with circular holes in their geometrical centers, stamping spiral grooves on the top and bottom of said blanks on the inner annular portion thereof, and bending the threaded portions substantially at right angles to the faces of said blanks.

17. A method for constructing a lamp-ishade frame member, consisting of stamping blanks from a strip of material substantially of circular shape with circular holes in their geometrical centers, stamping spiral grooves on the top and bottom of said blanks on the inner annular portion thereof, and bending the threaded portions substantially at right angles to the faces of said blanks, causing said spiral grooves to extend from the periphery of said circular holes outwards.

KORNEL BERGER. 

